import java.util.Scanner;
public class zeng {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个整数");
        int n = sc.nextInt();
        long jc = 1;
        for (int i = 1; i <= n; i++) {
            jc *= i;
        }
        System.out.println(n + "的阶乘为：" + jc);
    }
}